Packet-switch networks, such as the Internet, transport data between communicating devices using packets that are routed and switched across one or more links in a connection path. As packet-switched networks have grown in size and complexity, their role in the critical functioning of businesses, institutions, and organizations has increased dramatically.
Many types of packet processing devices have been designed to assist in getting business critical data from a source to destination in a timely and secure manner. In-line data inspection devices such as Intrusion Detection and Intrusion Prevention Systems (IDS & IPS) inspect traffic carried by the packets. Other devices connected at the edge of a network, transport network traffic across the network to one or more other network edge devices. Such network traffic may be transported using tunneling protocols, encapsulated packets, and may be encrypted to get the packets to the destination in a timely and secure manner.
Packet processing devices can be implemented as an in-line hardware and/or software based device that can perform deep packet inspection (DPI), examining the content encapsulated in a packet header or payload, regardless of protocol or application type and tracks the state of packet streams between network attached systems. Thus, in addition to routing and switching operations that networks carry out as they route and forward packets between sources and destinations, packet processing devices can introduce significant packet processing actions that are performed on packets as they travel from source to destination. Other network security methods and devices may similarly act on individual packets, packet streams, and other packet connections.
The performance of a system that utilizes the network services can vary based on how the traffic is delivered. For example, packets that carry the network traffic may not arrive at the destination in the same order as they where sent, the end node may have to reorder the data if the network does not provide an in-order data delivery service. The performance of the end node, and hence the whole system, may decrease if the end node has to reorder the data. If the network can provide an in-order data deliver service that reorders the delivered data, the whole system performance may increase.